gdb/common/signals.c

   1 /* Target signal translation functions for GDB.
   2    Copyright (C) 1990-2014 Free Software Foundation, Inc.
   3    Contributed by Cygnus Support.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "common-defs.h"
  21
  22 #ifdef HAVE_SIGNAL_H
  23 #include <signal.h>
  24 #endif
  25
  26 #include "gdb_signals.h"
  27
  28 struct gdbarch;
  29
  30 /* Always use __SIGRTMIN if it's available.  SIGRTMIN is the lowest
  31    _available_ realtime signal, not the lowest supported; glibc takes
  32    several for its own use.  */
  33
  34 #ifndef REALTIME_LO
  35 # if defined(__SIGRTMIN)
  36 #  define REALTIME_LO __SIGRTMIN
  37 #  define REALTIME_HI (__SIGRTMAX + 1)
  38 # elif defined(SIGRTMIN)
  39 #  define REALTIME_LO SIGRTMIN
  40 #  define REALTIME_HI (SIGRTMAX + 1)
  41 # endif
  42 #endif
  43
  44 /* This table must match in order and size the signals in enum
  45    gdb_signal.  */
  46
  47 static const struct {
  48   const char *symbol;
  49   const char *name;
  50   const char *string;
  51   } signals [] =
  52 {
  53 #define SET(symbol, constant, name, string) { #symbol, name, string },
  54 #include "gdb/signals.def"
  55 #undef SET
  56 };
  57
  58 const char *
  59 gdb_signal_to_symbol_string (enum gdb_signal sig)
  60 {
  61   gdb_assert ((int) sig >= GDB_SIGNAL_FIRST && (int) sig <= GDB_SIGNAL_LAST);
  62
  63   return signals[sig].symbol;
  64 }
  65
  66 /* Return the string for a signal.  */
  67 const char *
  68 gdb_signal_to_string (enum gdb_signal sig)
  69 {
  70   if ((int) sig >= GDB_SIGNAL_FIRST && (int) sig <= GDB_SIGNAL_LAST)
  71     return signals[sig].string;
  72   else
  73     return signals[GDB_SIGNAL_UNKNOWN].string;
  74 }
  75
  76 /* Return the name for a signal.  */
  77 const char *
  78 gdb_signal_to_name (enum gdb_signal sig)
  79 {
  80   if ((int) sig >= GDB_SIGNAL_FIRST && (int) sig <= GDB_SIGNAL_LAST
  81       && signals[sig].name != NULL)
  82     return signals[sig].name;
  83   else
  84     /* I think the code which prints this will always print it along
  85        with the string, so no need to be verbose (very old comment).  */
  86     return "?";
  87 }
  88
  89 /* Given a name, return its signal.  */
  90 enum gdb_signal
  91 gdb_signal_from_name (const char *name)
  92 {
  93   enum gdb_signal sig;
  94
  95   /* It's possible we also should allow "SIGCLD" as well as "SIGCHLD"
  96      for GDB_SIGNAL_SIGCHLD.  SIGIOT, on the other hand, is more
  97      questionable; seems like by now people should call it SIGABRT
  98      instead.  */
  99
 100   /* This ugly cast brought to you by the native VAX compiler.  */
 101   for (sig = GDB_SIGNAL_HUP;
 102        sig < GDB_SIGNAL_LAST;
 103        sig = (enum gdb_signal) ((int) sig + 1))
 104     if (signals[sig].name != NULL
 105         && strcmp (name, signals[sig].name) == 0)
 106       return sig;
 107   return GDB_SIGNAL_UNKNOWN;
 108 }
 109 \f
 110 /* The following functions are to help certain targets deal
 111    with the signal/waitstatus stuff.  They could just as well be in
 112    a file called native-utils.c or unixwaitstatus-utils.c or whatever.  */
 113
 114 /* Convert host signal to our signals.  */
 115 enum gdb_signal
 116 gdb_signal_from_host (int hostsig)
 117 {
 118   /* A switch statement would make sense but would require special
 119      kludges to deal with the cases where more than one signal has the
 120      same number.  Signals are ordered ANSI-standard signals first,
 121      other signals second, with signals in each block ordered by their
 122      numerical values on a typical POSIX platform.  */
 123
 124   if (hostsig == 0)
 125     return GDB_SIGNAL_0;
 126
 127   /* SIGINT, SIGILL, SIGABRT, SIGFPE, SIGSEGV and SIGTERM
 128      are ANSI-standard signals and are always available.  */
 129   if (hostsig == SIGINT)
 130     return GDB_SIGNAL_INT;
 131   if (hostsig == SIGILL)
 132     return GDB_SIGNAL_ILL;
 133   if (hostsig == SIGABRT)
 134     return GDB_SIGNAL_ABRT;
 135   if (hostsig == SIGFPE)
 136     return GDB_SIGNAL_FPE;
 137   if (hostsig == SIGSEGV)
 138     return GDB_SIGNAL_SEGV;
 139   if (hostsig == SIGTERM)
 140     return GDB_SIGNAL_TERM;
 141
 142   /* All other signals need preprocessor conditionals.  */
 143 #if defined (SIGHUP)
 144   if (hostsig == SIGHUP)
 145     return GDB_SIGNAL_HUP;
 146 #endif
 147 #if defined (SIGQUIT)
 148   if (hostsig == SIGQUIT)
 149     return GDB_SIGNAL_QUIT;
 150 #endif
 151 #if defined (SIGTRAP)
 152   if (hostsig == SIGTRAP)
 153     return GDB_SIGNAL_TRAP;
 154 #endif
 155 #if defined (SIGEMT)
 156   if (hostsig == SIGEMT)
 157     return GDB_SIGNAL_EMT;
 158 #endif
 159 #if defined (SIGKILL)
 160   if (hostsig == SIGKILL)
 161     return GDB_SIGNAL_KILL;
 162 #endif
 163 #if defined (SIGBUS)
 164   if (hostsig == SIGBUS)
 165     return GDB_SIGNAL_BUS;
 166 #endif
 167 #if defined (SIGSYS)
 168   if (hostsig == SIGSYS)
 169     return GDB_SIGNAL_SYS;
 170 #endif
 171 #if defined (SIGPIPE)
 172   if (hostsig == SIGPIPE)
 173     return GDB_SIGNAL_PIPE;
 174 #endif
 175 #if defined (SIGALRM)
 176   if (hostsig == SIGALRM)
 177     return GDB_SIGNAL_ALRM;
 178 #endif
 179 #if defined (SIGUSR1)
 180   if (hostsig == SIGUSR1)
 181     return GDB_SIGNAL_USR1;
 182 #endif
 183 #if defined (SIGUSR2)
 184   if (hostsig == SIGUSR2)
 185     return GDB_SIGNAL_USR2;
 186 #endif
 187 #if defined (SIGCLD)
 188   if (hostsig == SIGCLD)
 189     return GDB_SIGNAL_CHLD;
 190 #endif
 191 #if defined (SIGCHLD)
 192   if (hostsig == SIGCHLD)
 193     return GDB_SIGNAL_CHLD;
 194 #endif
 195 #if defined (SIGPWR)
 196   if (hostsig == SIGPWR)
 197     return GDB_SIGNAL_PWR;
 198 #endif
 199 #if defined (SIGWINCH)
 200   if (hostsig == SIGWINCH)
 201     return GDB_SIGNAL_WINCH;
 202 #endif
 203 #if defined (SIGURG)
 204   if (hostsig == SIGURG)
 205     return GDB_SIGNAL_URG;
 206 #endif
 207 #if defined (SIGIO)
 208   if (hostsig == SIGIO)
 209     return GDB_SIGNAL_IO;
 210 #endif
 211 #if defined (SIGPOLL)
 212   if (hostsig == SIGPOLL)
 213     return GDB_SIGNAL_POLL;
 214 #endif
 215 #if defined (SIGSTOP)
 216   if (hostsig == SIGSTOP)
 217     return GDB_SIGNAL_STOP;
 218 #endif
 219 #if defined (SIGTSTP)
 220   if (hostsig == SIGTSTP)
 221     return GDB_SIGNAL_TSTP;
 222 #endif
 223 #if defined (SIGCONT)
 224   if (hostsig == SIGCONT)
 225     return GDB_SIGNAL_CONT;
 226 #endif
 227 #if defined (SIGTTIN)
 228   if (hostsig == SIGTTIN)
 229     return GDB_SIGNAL_TTIN;
 230 #endif
 231 #if defined (SIGTTOU)
 232   if (hostsig == SIGTTOU)
 233     return GDB_SIGNAL_TTOU;
 234 #endif
 235 #if defined (SIGVTALRM)
 236   if (hostsig == SIGVTALRM)
 237     return GDB_SIGNAL_VTALRM;
 238 #endif
 239 #if defined (SIGPROF)
 240   if (hostsig == SIGPROF)
 241     return GDB_SIGNAL_PROF;
 242 #endif
 243 #if defined (SIGXCPU)
 244   if (hostsig == SIGXCPU)
 245     return GDB_SIGNAL_XCPU;
 246 #endif
 247 #if defined (SIGXFSZ)
 248   if (hostsig == SIGXFSZ)
 249     return GDB_SIGNAL_XFSZ;
 250 #endif
 251 #if defined (SIGWIND)
 252   if (hostsig == SIGWIND)
 253     return GDB_SIGNAL_WIND;
 254 #endif
 255 #if defined (SIGPHONE)
 256   if (hostsig == SIGPHONE)
 257     return GDB_SIGNAL_PHONE;
 258 #endif
 259 #if defined (SIGLOST)
 260   if (hostsig == SIGLOST)
 261     return GDB_SIGNAL_LOST;
 262 #endif
 263 #if defined (SIGWAITING)
 264   if (hostsig == SIGWAITING)
 265     return GDB_SIGNAL_WAITING;
 266 #endif
 267 #if defined (SIGCANCEL)
 268   if (hostsig == SIGCANCEL)
 269     return GDB_SIGNAL_CANCEL;
 270 #endif
 271 #if defined (SIGLWP)
 272   if (hostsig == SIGLWP)
 273     return GDB_SIGNAL_LWP;
 274 #endif
 275 #if defined (SIGDANGER)
 276   if (hostsig == SIGDANGER)
 277     return GDB_SIGNAL_DANGER;
 278 #endif
 279 #if defined (SIGGRANT)
 280   if (hostsig == SIGGRANT)
 281     return GDB_SIGNAL_GRANT;
 282 #endif
 283 #if defined (SIGRETRACT)
 284   if (hostsig == SIGRETRACT)
 285     return GDB_SIGNAL_RETRACT;
 286 #endif
 287 #if defined (SIGMSG)
 288   if (hostsig == SIGMSG)
 289     return GDB_SIGNAL_MSG;
 290 #endif
 291 #if defined (SIGSOUND)
 292   if (hostsig == SIGSOUND)
 293     return GDB_SIGNAL_SOUND;
 294 #endif
 295 #if defined (SIGSAK)
 296   if (hostsig == SIGSAK)
 297     return GDB_SIGNAL_SAK;
 298 #endif
 299 #if defined (SIGPRIO)
 300   if (hostsig == SIGPRIO)
 301     return GDB_SIGNAL_PRIO;
 302 #endif
 303
 304   /* Mach exceptions.  Assumes that the values for EXC_ are positive! */
 305 #if defined (EXC_BAD_ACCESS) && defined (_NSIG)
 306   if (hostsig == _NSIG + EXC_BAD_ACCESS)
 307     return GDB_EXC_BAD_ACCESS;
 308 #endif
 309 #if defined (EXC_BAD_INSTRUCTION) && defined (_NSIG)
 310   if (hostsig == _NSIG + EXC_BAD_INSTRUCTION)
 311     return GDB_EXC_BAD_INSTRUCTION;
 312 #endif
 313 #if defined (EXC_ARITHMETIC) && defined (_NSIG)
 314   if (hostsig == _NSIG + EXC_ARITHMETIC)
 315     return GDB_EXC_ARITHMETIC;
 316 #endif
 317 #if defined (EXC_EMULATION) && defined (_NSIG)
 318   if (hostsig == _NSIG + EXC_EMULATION)
 319     return GDB_EXC_EMULATION;
 320 #endif
 321 #if defined (EXC_SOFTWARE) && defined (_NSIG)
 322   if (hostsig == _NSIG + EXC_SOFTWARE)
 323     return GDB_EXC_SOFTWARE;
 324 #endif
 325 #if defined (EXC_BREAKPOINT) && defined (_NSIG)
 326   if (hostsig == _NSIG + EXC_BREAKPOINT)
 327     return GDB_EXC_BREAKPOINT;
 328 #endif
 329
 330 #if defined (SIGINFO)
 331   if (hostsig == SIGINFO)
 332     return GDB_SIGNAL_INFO;
 333 #endif
 334
 335 #if defined (REALTIME_LO)
 336   if (hostsig >= REALTIME_LO && hostsig < REALTIME_HI)
 337     {
 338       /* This block of GDB_SIGNAL_REALTIME value is in order.  */
 339       if (33 <= hostsig && hostsig <= 63)
 340         return (enum gdb_signal)
 341           (hostsig - 33 + (int) GDB_SIGNAL_REALTIME_33);
 342       else if (hostsig == 32)
 343         return GDB_SIGNAL_REALTIME_32;
 344       else if (64 <= hostsig && hostsig <= 127)
 345         return (enum gdb_signal)
 346           (hostsig - 64 + (int) GDB_SIGNAL_REALTIME_64);
 347       else
 348         error (_("GDB bug: target.c (gdb_signal_from_host): "
 349                "unrecognized real-time signal"));
 350     }
 351 #endif
 352
 353   return GDB_SIGNAL_UNKNOWN;
 354 }
 355
 356 /* Convert a OURSIG (an enum gdb_signal) to the form used by the
 357    target operating system (refered to as the ``host'') or zero if the
 358    equivalent host signal is not available.  Set/clear OURSIG_OK
 359    accordingly. */
 360
 361 static int
 362 do_gdb_signal_to_host (enum gdb_signal oursig,
 363                           int *oursig_ok)
 364 {
 365   int retsig;
 366   /* Silence the 'not used' warning, for targets that
 367      do not support signals.  */
 368   (void) retsig;
 369
 370   /* Signals are ordered ANSI-standard signals first, other signals
 371      second, with signals in each block ordered by their numerical
 372      values on a typical POSIX platform.  */
 373
 374   *oursig_ok = 1;
 375   switch (oursig)
 376     {
 377     case GDB_SIGNAL_0:
 378       return 0;
 379
 380       /* SIGINT, SIGILL, SIGABRT, SIGFPE, SIGSEGV and SIGTERM
 381          are ANSI-standard signals and are always available.  */
 382     case GDB_SIGNAL_INT:
 383       return SIGINT;
 384     case GDB_SIGNAL_ILL:
 385       return SIGILL;
 386     case GDB_SIGNAL_ABRT:
 387       return SIGABRT;
 388     case GDB_SIGNAL_FPE:
 389       return SIGFPE;
 390     case GDB_SIGNAL_SEGV:
 391       return SIGSEGV;
 392     case GDB_SIGNAL_TERM:
 393       return SIGTERM;
 394
 395       /* All other signals need preprocessor conditionals.  */
 396 #if defined (SIGHUP)
 397     case GDB_SIGNAL_HUP:
 398       return SIGHUP;
 399 #endif
 400 #if defined (SIGQUIT)
 401     case GDB_SIGNAL_QUIT:
 402       return SIGQUIT;
 403 #endif
 404 #if defined (SIGTRAP)
 405     case GDB_SIGNAL_TRAP:
 406       return SIGTRAP;
 407 #endif
 408 #if defined (SIGEMT)
 409     case GDB_SIGNAL_EMT:
 410       return SIGEMT;
 411 #endif
 412 #if defined (SIGKILL)
 413     case GDB_SIGNAL_KILL:
 414       return SIGKILL;
 415 #endif
 416 #if defined (SIGBUS)
 417     case GDB_SIGNAL_BUS:
 418       return SIGBUS;
 419 #endif
 420 #if defined (SIGSYS)
 421     case GDB_SIGNAL_SYS:
 422       return SIGSYS;
 423 #endif
 424 #if defined (SIGPIPE)
 425     case GDB_SIGNAL_PIPE:
 426       return SIGPIPE;
 427 #endif
 428 #if defined (SIGALRM)
 429     case GDB_SIGNAL_ALRM:
 430       return SIGALRM;
 431 #endif
 432 #if defined (SIGUSR1)
 433     case GDB_SIGNAL_USR1:
 434       return SIGUSR1;
 435 #endif
 436 #if defined (SIGUSR2)
 437     case GDB_SIGNAL_USR2:
 438       return SIGUSR2;
 439 #endif
 440 #if defined (SIGCHLD) || defined (SIGCLD)
 441     case GDB_SIGNAL_CHLD:
 442 #if defined (SIGCHLD)
 443       return SIGCHLD;
 444 #else
 445       return SIGCLD;
 446 #endif
 447 #endif /* SIGCLD or SIGCHLD */
 448 #if defined (SIGPWR)
 449     case GDB_SIGNAL_PWR:
 450       return SIGPWR;
 451 #endif
 452 #if defined (SIGWINCH)
 453     case GDB_SIGNAL_WINCH:
 454       return SIGWINCH;
 455 #endif
 456 #if defined (SIGURG)
 457     case GDB_SIGNAL_URG:
 458       return SIGURG;
 459 #endif
 460 #if defined (SIGIO)
 461     case GDB_SIGNAL_IO:
 462       return SIGIO;
 463 #endif
 464 #if defined (SIGPOLL)
 465     case GDB_SIGNAL_POLL:
 466       return SIGPOLL;
 467 #endif
 468 #if defined (SIGSTOP)
 469     case GDB_SIGNAL_STOP:
 470       return SIGSTOP;
 471 #endif
 472 #if defined (SIGTSTP)
 473     case GDB_SIGNAL_TSTP:
 474       return SIGTSTP;
 475 #endif
 476 #if defined (SIGCONT)
 477     case GDB_SIGNAL_CONT:
 478       return SIGCONT;
 479 #endif
 480 #if defined (SIGTTIN)
 481     case GDB_SIGNAL_TTIN:
 482       return SIGTTIN;
 483 #endif
 484 #if defined (SIGTTOU)
 485     case GDB_SIGNAL_TTOU:
 486       return SIGTTOU;
 487 #endif
 488 #if defined (SIGVTALRM)
 489     case GDB_SIGNAL_VTALRM:
 490       return SIGVTALRM;
 491 #endif
 492 #if defined (SIGPROF)
 493     case GDB_SIGNAL_PROF:
 494       return SIGPROF;
 495 #endif
 496 #if defined (SIGXCPU)
 497     case GDB_SIGNAL_XCPU:
 498       return SIGXCPU;
 499 #endif
 500 #if defined (SIGXFSZ)
 501     case GDB_SIGNAL_XFSZ:
 502       return SIGXFSZ;
 503 #endif
 504 #if defined (SIGWIND)
 505     case GDB_SIGNAL_WIND:
 506       return SIGWIND;
 507 #endif
 508 #if defined (SIGPHONE)
 509     case GDB_SIGNAL_PHONE:
 510       return SIGPHONE;
 511 #endif
 512 #if defined (SIGLOST)
 513     case GDB_SIGNAL_LOST:
 514       return SIGLOST;
 515 #endif
 516 #if defined (SIGWAITING)
 517     case GDB_SIGNAL_WAITING:
 518       return SIGWAITING;
 519 #endif
 520 #if defined (SIGCANCEL)
 521     case GDB_SIGNAL_CANCEL:
 522       return SIGCANCEL;
 523 #endif
 524 #if defined (SIGLWP)
 525     case GDB_SIGNAL_LWP:
 526       return SIGLWP;
 527 #endif
 528 #if defined (SIGDANGER)
 529     case GDB_SIGNAL_DANGER:
 530       return SIGDANGER;
 531 #endif
 532 #if defined (SIGGRANT)
 533     case GDB_SIGNAL_GRANT:
 534       return SIGGRANT;
 535 #endif
 536 #if defined (SIGRETRACT)
 537     case GDB_SIGNAL_RETRACT:
 538       return SIGRETRACT;
 539 #endif
 540 #if defined (SIGMSG)
 541     case GDB_SIGNAL_MSG:
 542       return SIGMSG;
 543 #endif
 544 #if defined (SIGSOUND)
 545     case GDB_SIGNAL_SOUND:
 546       return SIGSOUND;
 547 #endif
 548 #if defined (SIGSAK)
 549     case GDB_SIGNAL_SAK:
 550       return SIGSAK;
 551 #endif
 552 #if defined (SIGPRIO)
 553     case GDB_SIGNAL_PRIO:
 554       return SIGPRIO;
 555 #endif
 556
 557       /* Mach exceptions.  Assumes that the values for EXC_ are positive! */
 558 #if defined (EXC_BAD_ACCESS) && defined (_NSIG)
 559     case GDB_EXC_BAD_ACCESS:
 560       return _NSIG + EXC_BAD_ACCESS;
 561 #endif
 562 #if defined (EXC_BAD_INSTRUCTION) && defined (_NSIG)
 563     case GDB_EXC_BAD_INSTRUCTION:
 564       return _NSIG + EXC_BAD_INSTRUCTION;
 565 #endif
 566 #if defined (EXC_ARITHMETIC) && defined (_NSIG)
 567     case GDB_EXC_ARITHMETIC:
 568       return _NSIG + EXC_ARITHMETIC;
 569 #endif
 570 #if defined (EXC_EMULATION) && defined (_NSIG)
 571     case GDB_EXC_EMULATION:
 572       return _NSIG + EXC_EMULATION;
 573 #endif
 574 #if defined (EXC_SOFTWARE) && defined (_NSIG)
 575     case GDB_EXC_SOFTWARE:
 576       return _NSIG + EXC_SOFTWARE;
 577 #endif
 578 #if defined (EXC_BREAKPOINT) && defined (_NSIG)
 579     case GDB_EXC_BREAKPOINT:
 580       return _NSIG + EXC_BREAKPOINT;
 581 #endif
 582
 583 #if defined (SIGINFO)
 584     case GDB_SIGNAL_INFO:
 585       return SIGINFO;
 586 #endif
 587
 588     default:
 589 #if defined (REALTIME_LO)
 590       retsig = 0;
 591
 592       if (oursig >= GDB_SIGNAL_REALTIME_33
 593           && oursig <= GDB_SIGNAL_REALTIME_63)
 594         {
 595           /* This block of signals is continuous, and
 596              GDB_SIGNAL_REALTIME_33 is 33 by definition.  */
 597           retsig = (int) oursig - (int) GDB_SIGNAL_REALTIME_33 + 33;
 598         }
 599       else if (oursig == GDB_SIGNAL_REALTIME_32)
 600         {
 601           /* GDB_SIGNAL_REALTIME_32 isn't contiguous with
 602              GDB_SIGNAL_REALTIME_33.  It is 32 by definition.  */
 603           retsig = 32;
 604         }
 605       else if (oursig >= GDB_SIGNAL_REALTIME_64
 606           && oursig <= GDB_SIGNAL_REALTIME_127)
 607         {
 608           /* This block of signals is continuous, and
 609              GDB_SIGNAL_REALTIME_64 is 64 by definition.  */
 610           retsig = (int) oursig - (int) GDB_SIGNAL_REALTIME_64 + 64;
 611         }
 612
 613       if (retsig >= REALTIME_LO && retsig < REALTIME_HI)
 614         return retsig;
 615 #endif
 616
 617       *oursig_ok = 0;
 618       return 0;
 619     }
 620 }
 621
 622 int
 623 gdb_signal_to_host_p (enum gdb_signal oursig)
 624 {
 625   int oursig_ok;
 626   do_gdb_signal_to_host (oursig, &oursig_ok);
 627   return oursig_ok;
 628 }
 629
 630 int
 631 gdb_signal_to_host (enum gdb_signal oursig)
 632 {
 633   int oursig_ok;
 634   int targ_signo = do_gdb_signal_to_host (oursig, &oursig_ok);
 635   if (!oursig_ok)
 636     {
 637       /* The user might be trying to do "signal SIGSAK" where this system
 638          doesn't have SIGSAK.  */
 639       warning (_("Signal %s does not exist on this system."),
 640                gdb_signal_to_name (oursig));
 641       return 0;
 642     }
 643   else
 644     return targ_signo;
 645 }